package com.class05.j_polymorphic;

public interface USB {
    //    jdk7之前的特性
    int a = 10;//常量 public static final

    public abstract void open();

    public abstract void close();

    public default void test() {
        System.out.println("test");
    }

    public static void test2() {
        System.out.println("test2");
    }
}
